Re: [PATCH] Revert "cpufreq: schedutil: Don't restrict kthread to related_cpus unnecessarily"

[Quentin Perret]

On Tuesday 08 May 2018 at 16:44:51 (+0530), Viresh Kumar wrote:
> On 08-05-18, 12:00, Quentin Perret wrote:
> > Right, I see your point. Now, with the current implementation, why should
> > we randomly force a CPU to manage the kthread of another ? IIUC deadline
> > should assign the kthreads to CPUs depending on the state of the system
> > when the task is created. So, from one boot to another, you could
> > theoretically end up with varying configurations, and varying power/perf
> > numbers.
> 
> Yeah, if it is fixed at boot then there is no good reason to push it
> to any other CPU. I agree.
> 

To be fair, I think that DL tasks _can_ migrate, but only in special
conditions (hotplug, or if a DL task wakes up when another DL task is
running and things like that IIRC) but that probably doesn't matter much
for our discussion here.

Thanks,
Quentin